In many industrial applications, it is desireable to remove a surface imperfection such as a burr or a weld bead in a manner which leaves the surface perfectly smooth. Accordingly, hand held grinders or sanders are conventionally employed to this end. Such grinders or sanders generally fall into two classes: broad abrasive belt devices and relatively narrow abrasive belt devices. In each of these classes the devices may be further subdivided into vibrating belt and endless belt devices in which the endless belt is entrained over a pulley or support member.
Of the various types of grinders or sanders available, the narrow endless belt variety has found wide industrial acceptance due to its maneuverability, flexibility in confined areas and small relative cost. One such device is exemplified in U.S. Pat. No. 3,427,757. However, when one attempts to use such a grinder for removing an elongated ridge from a planar surface, such as a longitudinally extending weld bead, difficulties may be encountered. The hand held grinder is apt to slew from side to side or to gouge below the surface of the workpiece to produce a marred, uneven or otherwise generally unsatisfactory finished product. It is therefore evident that a need exists for an apparatus which enables a hand held, narrow, endless abrading belt grinder device to be used for grinding surface imperfections in a manner which results in a perfectly smooth and even finished planar surface. The apparatus should furthermore be easily adjustable to compensate for changes in thickness of the abrasive belt as it wears or when a belt of different thickness is substituted for the previously used belt.